Data security method and system

1. A method of verifying integrity of a digital file comprising: labeling, in a first network, the digital file prior to exposure to a foreign environment, the first network having a first security classification level, wherein labeling comprises: creating a header label comprising an identification of the first security classification level; appending the header label to the digital file; hashing the digital file, together with the appended header label, to obtain a first hash value; signing the first hash value to create a digital signature; creating a signature label comprising one or both of the first hash value and the digital signature; and appending the signature label to the digital file; and validating, in a second network, the digital file subsequent to exposure to the foreign environment, the second network having a second security classification level that is different from the first security classification level, wherein validating comprises: hashing the digital file to obtain a second hash value; retrieving the first hash value from the signature label; comparing the first hash value and second hash value; and removing the signature label from the digital file.

2. The method of verifying integrity of a digital file of claim 1 , the validating the digital file subsequent to exposure to the foreign environment further comprising removing the header label from the digital file.

3. The method of verifying integrity of a digital file of claim 1 , further comprising: performing a second labeling, in the first network, on the digital file prior to exposure to the foreign environment, wherein labeling comprises: creating a second header label comprising an identification of a third security classification level; appending the second header label to the digital file; hashing the digital file, together with the second header label, to obtain a third hash value; signing the third hash value to create a second digital signature; creating a second signature label comprising one or both of the third hash value and the second digital signature; and appending the second signature label to the digital file.

4. The method of verifying integrity of a digital file of claim 1 , further comprising: verifying, before release to the foreign environment, that the digital file has been authorized for release to the foreign environment.

5. The method of verifying integrity of a digital file of claim 4 , wherein verifying comprises: hashing the digital file to obtain a third hash value; retrieving the first hash value from the signature label; and comparing the first hash value and third hash value.

6. A method of verifying integrity of a digital file comprising: labeling the digital file prior to exposure to a foreign environment, wherein labeling comprises: creating a header label comprising an identification of a security classification level of a network; appending the header label to the digital file; hashing the digital file, together with the appended header label, to obtain a first hash value; signing the first hash value to create a digital signature; creating a signature label comprising one or both of the first hash value and the digital signature; and appending the signature label to the digital file.

7. The method of verifying integrity of a digital file of claim 6 , further comprising: validating the digital file subsequent to exposure to the foreign environment, wherein validating comprises: hashing the digital file, together with the appended header label, to obtain a second hash value; retrieving the first hash value from the signature label; and comparing the first hash value and second hash value.

8. The method of verifying integrity of a digital file of claim 7 , further comprising removing the signature label from the digital file after validating the digital file.

9. The method of verifying integrity of a digital file of claim 7 , wherein validating the digital file subsequent to exposure to the foreign environment further comprises removing the header label from the digital file.

10. The method of verifying integrity of a digital file of claim 6 , wherein appending the signature label to the digital file renders the digital file unreadable until the signature label is removed from the digital file.

11. A method of verifying integrity of a digital file comprising: receiving, in a first network, the digital file subsequent to exposure to a foreign environment, the first network having a first security classification level, the digital file comprising: an appended header label comprising an identification of a second security classification level of a second network, the second security classification level being different from the first security classification level; and an appended signature label comprising one or both of a first hash value and a digital signature; and validating the digital file, wherein validating comprises: hashing the digital file, together with the appended header label, to obtain a second hash value; retrieving the first hash value from the signature label; and comparing the first hash value and second hash value.

12. The method of verifying integrity of a digital file of claim 11 , further comprising: labeling the digital file prior to exposure to the foreign environment, wherein labeling comprises: hashing the digital file, together with the appended header label, to obtain the first hash value; signing the first hash value to create the digital signature; creating the signature label comprising one or both of the first hash value and the digital signature; and appending the signature label to the digital file.

13. The method of verifying integrity of a digital file of claim 11 , further comprising removing the signature label from the digital file after validating the digital file.

14. The method of verifying integrity of a digital file of claim 13 , wherein appending the signature label to the digital file renders the digital file unreadable until the signature label is removed from the digital file.

15. Logic encoded in non-transitory computer-readable media operable, when executed on a processor, to: label, in a first network, a digital file prior to exposure to a foreign environment, the first network having a first security classification level, wherein label comprises: creating a header label comprising an identification of the first security classification level; appending the header label to the digital file; hashing the digital file, together with the appended header label, to obtain a first hash value; signing the first hash value to create a digital signature; creating a signature label comprising one or both of the first hash value and the digital signature; and appending the signature label to the digital file; and validate, in a second network, the digital file subsequent to exposure to the foreign environment, the second network having a second security classification level that is different from the first security classification level, wherein validate comprises: hashing the digital file, together with the appended header label, to obtain a second hash value; retrieving the first hash value from the signature label; and comparing the first hash value and second hash value.

16. The logic encoded in computer-readable media of claim 15 , further operable, when executed on a processor, to remove the signature label from the digital file after validating the digital file.

17. The logic encoded in computer-readable media of claim 15 , wherein appending the signature label to the digital file renders the digital file unreadable until the signature label is removed from the digital file.

18. The logic encoded in computer-readable media of claim 15 , wherein validating the digital file subsequent to exposure to the foreign environment further comprises removing the header label from the digital file.